There are a number of different ODB2 scan tools out there, some PC based, some standalone units, some more for tuning and some more for diagnosing problems.
What are the different features that these devices provide? What are the pros/cons among different models? Is there one or two that "stand out from the crowd" as being the better ones?
Professionally I work with computers which diagnose Commercial vehicles (J1587, J1939 etc) so I'm somewhat familiar with how they work, but I'm totally new to the passenger vehicle space.
This is for my personal use, I have a few Nissans and a Subaru. Price wise I'd be interested to hear what the ranges are for a good one. I've seen them anywhere from $80 to several hundred.